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An experimental investigation of air bubble motion in a turbulent water stream
Author(s) -
Baker James L. L.,
Chao Bei T.
Publication year - 1965
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690110217
Subject(s) - reynolds number , bubble , turbulence , mechanics , drag , drag coefficient , radius , physics , thermodynamics , computer security , computer science
The motion of individual air bubbles in a water stream flowing turbulently in a 4 in. × 4 in. vertical conduit is investigated by photographic means. The bulk water velocity ranges from 40.8 to 267 cm./sec., corresponding to a system Reynolds number range of 48,600 to 386,000. Both tap and demineralized water were used at or near room temperatures. Air bubbles range from 0.038 to 0.70 cm. in equivalent radius and the corresponding bubble Reynolds number based on relative velocity ranges from 58 to 4,500. The results indicated that the bubble relative velocity in a turbulent water stream is similar to the rise velocity of single bubbles through a quiescent liquid. It was found to be practically independent of the system Reynolds number for bubbles having an equivalent radius above 0.3 cm. Large fluctuations in the bubble velocities were noted in all cases. The drag coefficient is, in general, lower for the demineralized water tests than for tap water when the bubble Reynolds number is below 2,000. Above this value, a mergence of the drag coefficients for all tests occur with a peak of approximately 2.0 at a bubble Reynolds number of 3,000, which is lower than the nonflow value of 2.6.